Transalkylation/disproportionation or thermal hydrodealkylation hydrocarbon processing methods and systems employing an increased ethylbenzene feed content

Patent metadata

Field	Value
Publication number	US-9815754-B2
Application number	US-201414472658-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2014
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Methods and apparatus for processing hydrocarbons are provided. In one example, a method for processing hydrocarbons includes the step of providing feed stream including toluene, ethylbenzene, mixed xylenes, and C 9 hydrocarbons. Ethylbenzene is present in the feed stream in an amount of at least about 20% by weight of total C 8 aromatic hydrocarbons present in the feed stream. The method further includes the step of subjecting the feed stream to ethylbenzene conversion to form a benzene-containing product stream that includes benzene.

First claim

What is claimed is:

1. A process for upgrading hydrocarbons comprising the steps of:
providing a feed stream comprising toluene, ethylbenzene, mixed xylenes, and C 9 hydrocarbons, wherein ethylbenzene is present in the feed stream in an amount of at least about 20% by weight of total C 8 aromatic hydrocarbons present in the feed stream;
dividing the feed stream into a first portion and a second portion in a first stream splitter;
separating the first portion of the feed stream in a first separation column into a first overhead stream and a first bottoms stream, the first overhead stream comprising toluene and lighter hydrocarbons and the first bottoms stream comprising ethylbenzene and heavier hydrocarbons;
dividing the first overhead stream into a first portion and a second portion in a second stream splitter;
combining the first bottoms stream and the second portion of the feed stream into a first combined stream;
separating the first combined stream in a second separation column into a second overhead stream and a second bottoms stream, the second overhead stream comprising ethylbenzene and lighter hydrocarbons, and the second bottoms stream comprising ethylbenzene, xylenes, and heavier hydrocarbons;
separating the second bottoms stream in a third separation column into a third overhead stream and a third bottoms stream, the third overhead stream comprising xylenes and lighter hydrocarbons and the third bottoms stream comprising C 9 and heavier hydrocarbons;
combining the first portion of the first overhead stream, the second overhead stream and the third bottoms stream into a second combined stream; and
converting at least a portion of the second combined stream into benzene in an ethylbenzene conversion zone to form a reaction product stream containing benzene.

2. The process of claim 1 further comprising:
separating the reaction product stream in a fourth separation column into an overhead fraction and a benzene containing product stream.

3. The process of claim 2 further comprising:
separating the benzene containing product stream in a fifth separation column into at least a benzene stream.

4. The process of claim 2 wherein the ethylbenzene conversion zone comprises a transalkylation/disproportionation zone and wherein the overhead fraction comprises an ethane rich gas.

5. The process of claim 2 wherein the ethylbenzene conversion zone comprises a thermal hydrodealkylation zone and wherein the overhead fraction comprises at least one of methane, ethane, and propane.

6. The process of claim 1 wherein the ethylbenzene conversion zone comprises a transalkylation/disproportionation zone and the reaction product stream further comprises xylenes.

7. The process of claim 1 wherein the reaction product stream further comprises unreacted ethylbenzene.

8. The process of claim 1 wherein at least one of the first, second, and third separation columns comprises a distillation column, a fractionation column, a splitter column, or combinations thereof.

9. The process of claim 1 wherein the second bottoms product stream comprises about 20% by weight or less of ethylbenzene.

10. The process of claim 1 wherein the first combined stream has a higher concentration of ethylbenzene and heavier hydrocarbons than the feed stream.

11. The process of claim 1 wherein the second combined stream has a lower concentration of xylenes than the feed stream.

12. The process of claim 1 further comprising increasing an amount of toluene in the second combined stream by increasing the first portion of the first overhead stream.

13. The process of claim 1 wherein the feed stream comprises a hydrotreated and extracted pygas stream.

Assignees

• Uop Llc

Inventors

• Sullivan Lawrence E
• Harrell Emily
• Xu Feng
• Noe Jason L

Classifications

• C07C4/16

  Thermal processes · CPC title

• C07C6/126 Primary

  of more than one hydrocarbon · CPC title

• C07C15/08

  Xylenes · CPC title

• C07C15/04

  Benzene · CPC title